yellow-blotched map turtles Graptemys fla imaculata from a historically contaminated site and a reference site

From May to September of 1998, we collected monthly plasma samples from male yellow-blotched map turtles Ž . captured at two sites in the Pascagoula River drainage, Mississippi. One site Vancleave has a documented history of Ž . pollution from industrial sources principally 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD . Fish consumption advisories at the Vancleave site were lifted in 1996 and current impacts appear minimal. However, the yellow-blotched map turtle, a federally protected species, continues to decline in numbers. To determine if endocrine disruption could be a factor in Ž . the low reproductive rates observed in Vancleave turtles, we examined levels of plasma testosterone T and Ž . Ž . estradiol-17 E from males at this site and a second site Leaksville , which has no known source of industrial 2 Ž . pollution. Plasma was also tested for vitellogenin VTG , which, in males, can be a biomarker of exposure to estrogenic contaminants. No males had detectable plasma VTG nor did mean monthly E levels differ between sites. However, 2 Ž 10% of males from the historically polluted site were found to have high levels of E equivalent to levels found in 2 . females and T was significantly lower for males captured at this site for 3 of 5 months. Our data suggest that the current impact of contaminants on reproduction in this population is limited. However, a portion of the population may have been affected developmentally, as represented by differences in reproductive parameters detected between sites. 2001 Elsevier Science Inc. All rights reserved.